Homo neanderthalensis essay

The discovery of the first fossilized remains of a human form in a small cave in the Neander Valley, Germany in August 1856, was the effective beginning of the discipline of paleoanthropology and has fuelled a contentious debate about nature of human evolution that is ongoing. Johann Karl Fuhlrott, an amateur naturalist, was given a collection of bones by local quarry workers.

Fuhlrott realized that these bones; a skull cap, femurs, three bones from the right arm and two from the left, a portion of the ilium and fragmented pieces of the scapula and ribs, represented a critical part of human history and consulted with an anatomist, Hermann Schaffhausen, to confirm the discovery. Taking its name from the site of discovery, the Homo neanderthalensis, William King announced the discovery of the new species in a scientific journal in1864. Although other fragments of H.

neanderthalensis fossils had been found earlier at sites in Engis, Belgium (1830) and Forbes Quarry, Gibraltar (1848), these had been assumed to be skeletal remains of recently deceased modern humans (Drell). The failure to properly recognize the fossilized remains as human was due to the prevailing belief in creationism – that God created humans. Publication of Charles Darwin’s “Origin of the Species” some three years after the discovery of the first Neanderthal remains was taken as evidence of the truth in Darwin’s theories of evolution and natural selection.

The contribution of Homo neanderthalensis to modern humans is controversial, with many believing that there is no relationship at all between anatomically modern hominids and the Neanderthals. Description of Homo neanderthalensis The skull and post-cranial morphology of Homo neanderthalensis are different to both archaic and modern Homo sapiens morphology, contributing to the argument that Neanderthals represent an evolutionary dead end, rather being the predecessors of modern humans (Harvati). The Neanderthal cranium is basic, with a distinctive protuberance on the occipital bone, commonly referred to as an occipital chignon or bun.

The mastoid processes are distinguished by a crest posterior to the external auditory meatus. Homo neanderthalensis’ jaw lacks a mental eminence, although the absence of chin appears to be less distinctive in later Neanderthal fossils. Neanderthal skulls are characterized by a heavily ridged brow and an extremely protruding mid-facial section, which terminates with large teeth below a broad nose (Ponce de Leon and Zollikofer). The extensive forward-projection of the nasal cavities is likely a cold-climate adaptation – the greater nasal surface would serve to warm cold air on inhalation.

It is thought that the large nasal sinuses developed early in the H. neanderthalensis life span because juvenile skeletons uncovered in Le Moustier (1906) and La Quina (1910) also possess this distinctive skeletal feature. Dentally, the Neanderthals were also different to modern hominids. Neanderthals lacked a canine fossa, but possessed instead a retromolar space. The fossil record shows that H. neanderthalensis typically had well-worn teeth, and it is probable that their forward-protruding facial structure was related to their chewing action.

Post-cranially, the Neanderthal skeleton differs from modern humans in five important aspects, namely; general skeletal robustness, tibial to femoral ratio, pelvic area, carpal-metacarpal joint articulation and the scapula. First, Neanderthal skeletons are characterized by large muscle attachment areas, especially on the long bones. The deltoid, pectoralis major and radial tuberosities are particularly large, indicating that Homo neanderthalensis was capable of powerful pronation and supination necessary to lift, crush and pull objects.

Femoral muscle attachment areas were also large, with heavily cartilaged knees and thick patellae. The skeletal adaptations to the knee are thought to accommodate rapid decelerations associated with jumping and breaking falls (Trinkaus). Both the tibia and femora of H. neanderthalensis have thickened internal walls, with both these bones being round in cross section. This indicates that the Neanderthals did not range over long distances and is a further difference between Homo neanderthalensis and later hominids, whose long bones were more tear-drop in cross section.

Further indication of the robusticity of Neanderthal skeletons is the prominent palmar tuberosities, which provide considerable muscular attachment areas, conferring great strength to the fingers and thumbs. The Homo neanderthalensis’ distal phalanges have circular tuberosities, suggesting that the fingertips and nails were often used for grasping, pinching and kneading objects (Trinkaus). Neanderthals also demonstrate a particularly interesting carpal-metacarpal joint, which offered greater raw gripping strength. The anatomical structure of this joint in modern hominids confers manipulative rather than strength advantages.

It was first thought that Neanderthal skeletal robustness was an anatomical adaptation to physical labor; however this theory was abandoned with the discovery of the fossilized remains of juvenile Neanderthal skeletons, which displayed the same characteristics. It is instead likely that Neanderthal’s general skeletal robusticity was a genetic trait, rather than an adaptive mechanism. In Neanderthals, the tibial to femoral ratios are small. The short, bowed legs of H. neanderthalensis are quite similar to modern Inuit and Lapp populations, fueling the argument that these skeletal traits are cold climate adaptation.

Strong evidence for the difference between Neanderthals and humans is found in the structure of the pelvis. Incomplete fragments of the Neanderthal pelvis at first led anthropologists to believe that the pelvic inlet was particularly large as the result of a longer gestation period. Discovery of the first complete pelvis in Kebara, Israel, revealed that the anatomical difference between Neanderthals and more recent hominids was simply a longer superior pubic ramus, whose purpose was probably a postural or locomotive adaptation, rather than a gynecological one (Rak and Arsenburg).

The Kebara pelvis was distinctively shaped, with the femoral sockets situated posteriorly to those of modern hominids, suggesting that the Neanderthals squatted habitually. Although bipedal, the gait of Homo neanderthalensis was awkward due to the posterior orientation of the femoral sockets. The posteriorly-ortientated femoral sockets are not seen in more modern hominids, again prompting speculation that the Neanderthals are not direct ancestors of the Homo sapiens species. The Neanderthal scapula is also distinctive.

It is medio-laterally wide, with high spines and a substantial distance between the acromion and axis of rotation. In comparison to modern humans, where muscles attach to the ventral sulcus, the fossil record indicates that in Homo neanderthalensis, the scapular sulcus was located on the larger dorsal scapular surface. This arrangement provided greater surface area for muscle attachment, hence enabling a powerful upper arm swing. Discussion The Neanderthals were a hunter-gatherer group that occupied Europe and Western Asia as far East as Soviet Central Asia and North to 52 degrees during the Upper Pleistocene era.

Aspects of the Neanderthal paleo-ecology and social behavior were unique to this population. In particular, the fossil record indicates that Homo neanderthalensis were the first population to develop Mousterian tools such as hand axes, scrapers, borers and knives, which were fashioned from flint stones. Neanderthal tools evolved little during their 100,000 year occupation of the Earth, and most did not include materials such as bone, antler or ivory – all of which could have been derived from their prey. Neanderthal use of Mousterian tools is important for several reasons.

First, it demonstrates that hunting of medium to large mammals was an essential component of the Homo neanderthalensis diet. Stable isotope analysis of bone collagen derived from the skeletal remains of Neanderthals in Croatia, France and Belgium indicates that Neanderthals were top-level carnivores who derived their dietary protein from animal sources (Richards et al. ). Animal remains found with Homo neanderthalensis are mostly reindeer, bison, elk and mammoth. Mousterian technology is also important because it reduced the Neanderthals’ reliance on their front teeth for environmental manipulation.

In addition, several social behaviors are unique to the species. The fossil record indicates that Homo neanderthalensis took care of their injured and partook of burial rites. Fossilized pollen has been discovered with some Neanderthal remains, suggesting that floral material may have been buried with the deceased. There is also fossil evidence of personal adornment. The evolutionary importance of the Neanderthals has continued to fuel debate amongst paleoanthropologists and the general public alike.

Two theories, the replacement model and multi-regional models have been put forward to explain the role of Homo neanderthalensis in human evolution. The multi-regional model of evolution identifies Neanderthals as at least partial ancestors of late Paleolithic and modern Europeans, with the strongest evidence for this argument being the Neanderthal-like features of some late Paleolithic Europeans (Harvati). By contrast, the replacement model opines that that the Neanderthals made little to no contribution to the evolution of modern humans.

It is argued that the fossil evidence supports replacement of the Neanderthals by another species, who migrated into Europe out of Africa (Harvati). Discovery of Homo neanderthalensis remains in Qafzeh, Israel is particularly important evidence for the replacement model, because it indicates that Neanderthals arrived in the region after the evolution of modern Homo sapiens and, whilst the two species may have co-existed, interbreeding between the species did not occur and the population of modern humans was not descended from H.

neanderthalensis. Sophisticated modern analytical techniques, particularly genetic testing, add weight to the replacement model. Analysis of mitochondrial DNA of Fuhlrott’s original Neanderthal revealed this specimen to be a distant outlier, when compared to all other modern human populations (Tattersall and Schwartz). Conclusions The discovery of Homo neanderthalensis ignited more than a century of debate about the specifics of human evolution. It provided solid scientific evidence against the prevailing Creationist beliefs of the 19th Century.

Several morphological features of the Neanderthals set them apart from earlier and later hominids. Distinctive features of Homo neanderthalensis included general skeletal robusticity and idiosyncratic pelvic, carpal-metacarpal and scapulars morphologies. Sophisticated analytical techniques support the replacement model of human evolution and suggest that Neanderthals are not direct ancestors of modern humans.

Works cited

Drell, J. R. R. “Neanderthals: A History of Interpretation. ” Oxford Journal of Archaeology 19.1 (2000): 1-24. Harvati, K. “The Neanderthal Taxonomic Position: Models of Intra- and Inter-Specific Craniofacial Variation. ” Journal of Human Evolution 44 (2003): 107-32. Ponce de Leon, M. S. , and C. P. Zollikofer. “Neanderthal Cranial Ontogeny and Its Implications for Late Hominid Diversity. ” Nature 412. 6846 (2001): 534-8. Rak, Y. , and B. Arsenburg. “Kebara 2 Neanderthal Pelvis: First Look at a Complete Inlet. ” American Journal of Physical Anthropology 73. 2 (1987): 227-31. Richards, M. P. , et al.

“Neanderthal Diet at Vindija and Neanderthal Predation: The Evidence from Stable Isotopes. ” Proceedings of the National Academy of Science of the United States of America 97. 13 (2000): 7663-66. Tattersall, I. , and J. H. Schwartz. “Hominids and Hybrids: The Place of Neanderthals in Human Evolution. ” Proceedings of the National Academy of Science of the United States of America 96. 13 (1999): 7117-19. Trinkaus, E. “The Neandertals and Modern Human Origins. ” Annual Review of Anthropology 15 (1986): 193-218.